In a working machine such as a backhoe, for example, a revolving control valve for a revolving motor that revolves a machine body, a boom control valve for a boom cylinder that swings a boom, an arm control valve for an arm cylinder that swings an arm, and a bucket control valve for a bucket cylinder that swings a bucket are respectively subjected to pilot operations by left and right controlling devices.
Each of the controlling devices is provided with: a pilot valve; and a controlling lever for controlling the pilot valve, and the controlling lever is adapted to be longitudinally and laterally operable with tilting.
Operation patterns of the left and right controlling devices include, for example, an operation pattern referred to as a so-called ISO pattern that is internationally unified. This operation pattern is one in which with one of the controlling levers, the arm control valve is operated by the lateral tilting operation, and the revolving control valve is operated by the longitudinal tilting operation, whereas with the other controlling lever, the bucket control valve is operated by the lateral tilting operation, and the boom control valve is operated by the longitudinal tilting operation.
Also, in a market, a working machine having an operation pattern other than the ISO pattern is active.
Accordingly, there is a working machine provided with an operation pattern switching device that can, in order to be able to select any of a plurality of operation patterns, switch an operation pattern of controlling devices to any of the plurality of operation patterns (see Japanese Unexamined Patent Publication JP-A2010-230121 and Japanese Patent No. 4846870).
In this working machine, in hydraulic pipe lines from the controlling devices to control valves, an operation pattern switching valve that switches an operation pattern is set, and the operation pattern switching valve is configured to include a rotary valve provided with a rotating spool in a valve body. The rotating spool is subjected to a switching operation by an operation lever, and locked by locking means so as not to move.
In the working machine described in Japanese Unexamined Patent Publication JP-A2010-230121, a lever bracket that rotates integrally with the rotating spool is provided with the operation lever, and by rotating the rotating spool with gripping the operation lever, the switching operation is performed. Also, the lever bracket is provided with an engaging piece to fix a fixing bracket to the valve body, and at a switching position of the rotating spool, the engaging piece of the lever bracket and the fixing bracket are fixed to each other with a bolt and a nut, whereby the rotating spool is locked so as not to move.
In the working machine described in Japanese Patent No. 4846870, the operation lever for performing the switching operation of the rotating spool is fixed to a shaft fixed to the rotating spool, and at a switching position of the rotating spool, a bolt screwed into a screw hole that is formed in the valve body with penetrating through the operation lever locks the rotating spool so as to prevent the rotating spool from moving.